Tissue modification methods and apparatus

ABSTRACT

A method and apparatus for treating a stricture in a body lumen. The method comprises (a) sensing pressure being exerted by a treatment device on the stricture, (b) determining if enough force is being exerted on the stricture, (c) if enough force is being exerted on the stricture, timing the application of enough force, (d) determining if too much force is being exerted by the treatment device on the stricture, (e) if too much force is being applied to the stricture, decrementing the force being applied to the stricture, (f) determining if not enough force is being applied to the stricture, (g) if not enough force is being applied to the stricture incrementing the force being applied to the stricture, and (h) repeating (a)-(g) until (i) a desired pressure has been maintained on the tissue for a desired time. The apparatus comprises a device for exerting pressure on the stricture, a controller for controlling the amount of pressure the device exerts on the stricture, and a pressure sensor for sensing the pressure being exerted on the stricture by the device.

BACKGROUND

Surgical procedures are frequently performed on human and animal bodylumens. For example, laryngectomies involve the esophagus and thetrachea. Such procedures often result in the formation of strictures ofscar tissue as the surgical sites heal. In many cases, these stricturescan continue to grow, progressively occluding the affected lumen(s).Attention to such sites is necessary to maintain the lumen(s) patent.Chemotherapy and radiation therapy can cause such strictures to form, ascan acid reflux disease. These also typically require attention.

In the past, surgical patients who experienced the growth of suchstrictures checked into the healthcare facility, typically a hospital orsurgical center, were placed under anesthesia, and had their stricturesbroken open. This, of course, required recovery not only from anesthesiabut also from the sometimes traumatic breaking open of the stricture.Such a patient might remain in the surgical center for several hours, orthe hospital overnight. Usually, the breaking open of the stricturewould be done by rapidly inflating a balloon of a balloon catheter whichhad been located in the stricture, either visually or by imaging means,such as X-ray, CT, endoscopy or the like. Alternatively, the surgeonmight use a series of bougies, passing bougies of increasing sizethrough the stricture until it would pass one of sufficient size toalleviate the problems associated with the stricture. This, of course,requires essentially continuous involvement by the surgeon as thebougies of increasing size are passed through the stricture, stretchingor breaking it. The surgeon would then have to attend to whatever traumaresulted from this treatment.

In another tissue modification application, patients who are undergoing,for example, breast remodeling surgery, burn surgery, or other types ofsurgery requiring skin grafts, are often treated to produce the requiredskin, so-called autologous grafts, for the remodeling or other surgerythemselves.

SUMMARY

According to an aspect of the invention, a stricture is modifiedincrementally by either fluid (pneumatic or hydraulic) means or bymechanical means. The fluid means typically comprises a balloon catheterwhich is supplied either with a gas or mixture of gases, typically,compressed air, or a liquid, typically, a saline solution, perhapscontaining a radiopaque contrast medium where that is desired.

The mechanical means typically includes multiple flexible ribs which areflexed outwardly by an actuator against the tissue, or a cylindrical,helically wound braid, such as a biaxial braid, or so-called “Chinesehandcuffs.” Illustratively, the material is TechFlex FlexoPET brandbraid. However, stainless steel or other material braid may be used asappropriate. The material from which the ribs or braid are constructedmay be treated to reduce microbial population, may be coated with a thinmembrane, or may be sterilizable. The ribs or braid are used “inreverse.” That is, an actuator, such as a control wire, extends throughthe interior of the assembly of ribs or the braid so that tension on thewire causes the cross sectional area of the assembly of ribs or the bodyof the braid (transverse to the longitudinal extent of the assembly ofribs or braid and transverse to the direction of pull of the controlwire) to increase. In use according to the invention, the assembly ofribs or braid is placed in the stricture so that the increasing crosssectional area or cross sectional aspect exerts a stretching force onthe stricture, enlarging it and relieving the patient's symptoms.

In order to reduce the trauma associated with the treatment ofstrictures, and in order to reduce the amount of the attendingphysician's time necessary for treatment, a programmable controllerincrementally controls the inflation of the balloon, in the case of thepneumatic or hydraulic devices, or the enlargement of the cross sectionof the mechanical device, in the case of the mechanical device.

According to an aspect of the invention, skin for remodeling, such asbreast reconstructions, can be promoted by implanting under the skin ofa patient either the fluid (pneumatic or hydraulic) device or themechanical device. The device (or devices of different sizes) is (are)then enlarged incrementally, causing the patient to produce additionalskin either for subsequent harvesting for (a) graft(s) or so that theremodeling can be conducted and there will be sufficient skin to coverit.

According to an aspect of the invention, a method for treating astricture in a body lumen comprises (a) sensing pressure being exertedby a treatment device on the stricture, (b) determining if enough forceis being exerted on the stricture, (c) if enough force is being exertedon the stricture, timing the application of enough force, (d)determining if too much force is being exerted by the treatment deviceon the stricture, (e) if too much force is being applied to thestricture, decrementing the force being applied to the stricture, (f)determining if not enough force is being applied to the stricture, (g)if not enough force is being applied to the stricture incrementing theforce being applied to the stricture, and (h) repeating (a)-(g) until(i) a desired pressure has been maintained on the tissue for a desiredtime.

According to an aspect of the invention, apparatus for treating astricture in a body lumen comprising a device for exerting pressure onthe stricture, a controller for controlling the amount of pressure thedevice exerts on the stricture, and a pressure sensor for sensing thepressure being exerted on the stricture by the device.

Illustratively according to this aspect, the device includes a syringe,an inflating fluid and a balloon catheter. The inflating fluid inflatesthe balloon of the catheter in the stricture incrementally, graduallyrelieving the stricture.

Illustratively according to this aspect, the device includes a motor, ascrew coupled to the motor, and a follower for following rotation of thescrew to advance and retract a plunger of the syringe to increase anddecrease, respectively, the pressure of the inflating fluid in theballoon.

Alternatively illustratively according to this aspect, the deviceincludes a mechanical expanding device. A proximal end of a control wireis coupled through a sheath to the device. Movement of the device movesthe control wire, moving the distal end of the device toward theproximal end of the device, reducing the length of the device andincreasing the device's cross sectional area or cross sectional aspecttransverse to the length in the stricture incrementally, graduallyrelieving the stricture.

Illustratively according to this aspect, the device includes a motorwhich drives a screw, a follower for following rotation of screw toadvance and retract the control wire to decrease and increase,respectively, the pressure of the device on the stricture.

Illustratively according to this aspect, the device includes a limitswitch to limit the pressure exerted by the device on the stricture.

According to an aspect of the invention, a method for remodeling tissuein a body comprises (a) sensing pressure being exerted by a treatmentdevice on the tissue, (b) determining if enough pressure is beingexerted by the device, (c) if enough pressure is being exerted by thedevice, timing the application of enough pressure, (d) determining iftoo much pressure is being exerted by the device, (e) if too muchpressure is being exerted by the device, decrementing the pressure beingexerted by the device, (f) determining if not enough pressure is beingexerted by the device, (g) if not enough pressure is being exerted bythe device incrementing the pressure being exerted by the device, and(h) repeating (a)-(g) until (i) a desired pressure has been maintainedon the tissue for a desired time.

According to an aspect of the invention, apparatus for remodeling tissuein a body comprises a device for exerting pressure on the tissue, acontroller for controlling the amount of pressure the device exerts onthe tissue, and a pressure sensor for sensing the pressure being exertedon the tissue by the device.

Illustratively according to this aspect, the device includes a syringe,an inflating fluid and a balloon catheter. The inflating fluid inflatesthe balloon of the catheter adjacent the tissue incrementally, graduallyremodeling the tissue.

Illustratively according to this aspect, the device includes a motor, ascrew coupled to the motor, and a follower for following rotation of thescrew to advance and retract a plunger of the syringe to increase anddecrease, respectively, the pressure of the inflating fluid in theballoon.

Alternatively illustratively according to this aspect, the deviceincludes a braid, a proximal end of a control wire coupled through asheath to the device. Movement of the device moves the control wire,moving the distal end of the device toward the proximal end of thedevice, reducing the length of the device and increasing the device'scross section transverse to the length adjacent the tissueincrementally, gradually remodeling the tissue.

Illustratively according to this aspect, the device includes a motorwhich drives a screw, a follower for following rotation of screw toadvance and retract the control wire to decrease and increase,respectively, the pressure of the device on the tissue.

Illustratively according to this aspect, the device includes a limitswitch to limit the pressure exerted by the device on the tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may best be understood by referring to the followingdetailed description and accompanying drawings which illustrate theinvention. In the drawings:

FIG. 1 illustrates a perspective view of a syringe pump constructedaccording to the invention;

FIG. 2 illustrates a perspective view of the syringe pump illustrated inFIG. 1, taken from the opposite end of the pump;

FIG. 3 illustrates a perspective view from the underside of the pumpillustrated in FIGS. 1-2;

FIG. 4 illustrates a view similar to FIG. 1, but with a balloon catheterfitted to the syringe of the pump;

FIG. 5 illustrates a view similar to FIG. 4, but with the ballooninflated;

FIG. 5A illustrates a somewhat enlarged fragmentary sectional view ofFIG. 5 taken along section lines 5A-5A thereof;

FIG. 6 illustrates the deflated balloon catheter of FIG. 4 oriented inan esophageal stricture;

FIG. 7 illustrates the balloon inflated in the stricture;

FIG. 8 illustrates a view similar to FIG. 1, but with a cylindrical,helically wound braid tipped sheathed control wire fitted to the syringeof the pump;

FIG. 9 illustrates a view similar to FIG. 8, but with the braid tipexpanded;

FIG. 10 illustrates the unexpanded braid tip of FIG. 8 oriented in anesophageal stricture;

FIG. 11 illustrates the expanded braid tip in the stricture;

FIGS. 12-17 illustrate electrical circuit diagram of a controller usefulto practice the invention;

FIGS. 18-21 illustrate a program flow diagram useful to practice theinvention;

FIG. 22 illustrates an enlarged fragmentary perspective view of anotherembodiment in an unexpanded condition;

FIG. 23 illustrates the embodiment illustrated in FIG. 22, but inexpanded condition; and,

FIG. 24 illustrates an enlarged fragmentary perspective view of anotherembodiment in an expanded condition.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring now to FIGS. 1-11 and 22-24, the apparatus includes a syringepump 100, such as, for example, a New Era model NE-510X syringe pumpavailable from New Era Pump Systems, Farmingdale, N.Y. Pump 100 includesan inverted U-shaped chassis 102 providing a top surface 104 upon whichthe syringe 106 is clamped and its plunger 108 manipulated, and anunderside 110 for housing the electronics 112 for controlling the pump100 are mounted. The electronics 112 include a stepper motor 114, suchas, for example, a Coact Model 17H185H-15P stepper motor, which drives ascrew 116 (FIG. 3) on its output shaft. A follower, or linear slide, 118follows the rotation of the screw 116 to advance and retract (dependingupon the direction of motor rotation) a block 120 into which the plunger108 is inserted. In this way, rotation of the motor 114 drives theplunger 108 under control of the electronics 112 which control the motor114.

In balloon catheter embodiments FIGS. 4-7, the plunger 108 forces aninflating fluid, typically air or water, out of the syringe 106 into theballoon 122, compare FIGS. 4 and 6 with FIGS. 5 and 7, to inflate theballoon 122 in the stricture 124 incrementally, gradually relieving thestricture 124. In the mechanical device embodiments, FIGS. 8-11 and22-24, a proximal end 126 of a control wire 128 is coupled through asheath 129 to the plunger 108. Withdrawal of the plunger 108 from thebarrel of the syringe 106 thus results in pulling of the control wire128. In braid embodiments, the control wire 128 pulls the distal end 130of the braid 132 toward the braid 132's proximal end 134, reducing itslength and increasing its cross section transverse to its length in thestricture 124, compare FIGS. 8 and 10 with FIGS. 9 and 11, incrementallycompressing and gradually relieving the stricture 124. In wire ribembodiments, the control wire 128′ pulls the distal end 130′ of the ribassembly 132′ toward the rib assembly 132's proximal end 134′, reducingits length and increasing its cross section transverse to its length inthe stricture 124, compare FIG. 22 with FIG. 23, incrementallycompressing and gradually relieving the stricture 124. As illustrated inFIG. 24, a distal end of control wire 128 can be provided with anenlargement 136 to spread the rib assembly 132″ in the stricture 124,instead of having the control wire 128, 128′ anchored to the distal end130, 130′ of the rib assembly 132, 132′.

The control wire 128 may be part of a bundle extending down the interiorof the sheath 129, the bundle including multiple optical fibers whichpermit the introduction of light adjacent the distal end 130, 130′ ofthe balloon 122, braid 132, or rib assembly 132′, at the tip of thecatheter, and the recovery of images of the stricture 124 site. Withreference to FIG. 5A, in balloon or mechanical embodiments, anadditional, small cross sectional area channel 138 can be provided inthe catheter wall 140. An access port can be provided at the syringepump 100 end and an exit port adjacent the balloon 122 or mechanicaldevice 132, 132′. This channel 138 permits the introduction at thesyringe pump 100 end of, for example, a topical anesthetic, a steroid,or other treatment substance, which is dispensed adjacent the balloon122 or mechanical device 132, 132′ to desensitize or treat tissueadjacent the stricture 124, if that is necessary or desirable. Thisdispensing can either be by aerosol or by threading a fine needle downthe channel 138 and injecting the medical substance adjacent thestricture 124.

The schematic and block circuit diagram descriptions that followidentify specific integrated circuits and other components and in manycases specific sources for these. Specific terminal and pin names andnumbers are generally given in connection with these for the purposes ofcompleteness. It is to be understood that these terminal and pinidentifiers are provided for these specifically identified components.It is to be understood that this does not constitute a representation,nor should any such representation be inferred, that the specificcomponents, component values or sources are the only componentsavailable from the same or any other sources capable of performing thenecessary functions. It is further to be understood that other suitablecomponents available from the same or different sources may not use thesame terminal/pin identifiers as those provided in this description.

Referring now to FIGS. 12-17, an electrical block and schematic diagramof the controller 200, a microcontroller (μC) 202, FIGS. 12-16, has its5V input terminal coupled to a terminal of a pressure sensor 204, FIG.13, such as, for example, the Sparkfun Electronics (Tekscan) Flexiforcemodel A401 or SEN11207 pressure sensor 204. Pressure sensor 204 ispositioned between facing surfaces of the plunger 108 and block 120 tosense pressure between these surfaces, and thereby, pressure on thestricture 124. μC 202 illustratively is an Arduino Uno μC or an Atmel8-bit, AVR, RISC-based ATmega328P μC. The other terminal of pressuresensor 204 is coupled to a terminal of a 10 KΩ rotary potentiometer 206,illustratively, a linear taper model 271-1715. Another terminal ofpotentiometer 206 is coupled to a GrouND terminal of μC 202. Anotherterminal of potentiometer 206 is coupled to the A0 terminal of μC 202.Potentiometer 206 permits fine pressure adjustment. The resistanceacross the series combination of pressure sensor 204 and potentiometer206 is monitored across the A0 and GND terminals of μC 202. This is ameasure of the pressure being exerted on sensor 204 by plunger 108.

Forward 208 and reverse 210 limit switches, FIG. 14, sense the endpointsof travel of block 120 and thus of plunger 108. Switches 208, 210illustratively are Yueqing Daier Electron Co., Ltd., model MSW-0switches. A terminal of switch 208 is coupled through a 10 KΩ resistorto 5V. The other terminal of switch 208 is coupled to pin 2 of μC 202. Aterminal of switch 210 is coupled through a 10 KΩ resistor to 5V. Theother terminal of switch 210 is coupled to pin 3 of μC 202. A controller200 START button 212 is coupled in series with a 10 KΩ resistor acrosspin 4 of μC 202 and 5V. START button 212 illustratively is a Radio Shackmodel NTE54-394 push button. A controller 200 ON indicator LED 214 iscoupled in series with a 220Ω resistor across pin 13 and a GND terminalof μC 202. LED 214 illustratively is a Radio Shack green LED withholder, model 276-069.

Referring to FIG. 15, the stepper motor 114 is driven from pins 8 and 9of μC 202 through a motor driver 216, such as a Sparkfun (Schmalzhaus)ROB10267 Easy Driver V4, or an Allegro A3967 driver chip. The GNDterminal of the driver 216 is coupled to the GND terminal of the μC 202.Pins 8 and 9 of μC 202 are coupled to pins DIRection and STEP,respectively, of driver 216. Power for the motor 114 is 12 VDC which iscoupled to the 12V terminal of driver 216. This voltage is regulated bya 5V power regulator 218, FIG. 16, the 12V terminal of which is alsocoupled to the 12V terminal of driver 216. The GND terminal of regulator218 is coupled to ground. The 5V terminal of regulator 218 provides thesystem 5V supply. Regulator 218 illustratively is a type LM317 powerregulator.

Controller 202 status, for example, the pressure being sensed by sensor204, is displayed on a display 220. Display 220 illustratively is aHitachi type HD44780 LCD or a Unitech model UC-204A LCD. Pins 1 and 5 ofdisplay 220 are coupled to ground. Pins 2 and 3 of display 220 arecoupled to two terminals of a 10 KΩ rotary potentiometer 222, FIG. 13. Aremaining terminal of potentiometer 222 is coupled to ground.Potentiometer 222 provides contrast control for display 220. Pins 4, 6and 11-14 of display 220 are coupled to pins 12-10 and 7-5,respectively, of μC 202. Pin 15 of display 220 is coupled to 5V. Pin 16of display 220 is coupled to ground.

A flow diagram of the program which controller 200 executes isillustrated in FIGS. 18-21. Referring first to FIG. 18, at step 300,variables, including the library, are initialized. At step 302, all stepvariables are cleared, and the display 200 is formatted. Referring toboth FIGS. 18 and 19, at step 304, “Press start button 212?” is queried.If step 304, “Press start button 212?” is YES, referring to FIG. 20,step 310, “Clear display 220, read sensor 204” is executed. If step 304,“Press start button 212?” is NO, referring to FIG. 19, step 306, “Islinear slide 118 in park?” is queried.

If step 306, “Is linear slide 118 in park?” is YES, step 307, “Flashready LED 214” is executed and the program returns to FIG. 18, step 302.If step 306, “Is linear slide 118 in park?” is NO, FIG. 19, step 308,“park linear slide 118, display ‘Returning’ on display 220,” isexecuted, and the program returns to FIG. 18, step 302.

From FIG. 20, step 310, “Clear display 220, read sensor 204,” at FIG.20, step 312, “Time to update display 220?” is queried. If step 312,“Time to update display 220?” is YES. at FIG. 20, step 314, “Updatedisplay 220 with sensor 204 reading,” is executed, and the programproceeds to FIG. 20, step 315, “Dilation force and time reached?” Ifstep 312, “Time to update display 220?” is NO, the program proceeds toFIG. 20, step 315, “Dilation force and time reached?”

If FIG. 20, step 315, “Dilation force and time reached?” is YES, theprogram proceeds to FIG. 19, step 308 “park linear slide 118, display‘Returning’ on display 220,” is executed, and the program returns toFIG. 18, step 302. If FIG. 20, step 315, “Dilation force and timereached?” is NO, the program proceeds to FIGS. 20-21, step 316, “Reverselimit switch 210 reached?”

If FIGS. 20-21, step 316, “Reverse limit switch 210 reached?” is YES,the program proceeds to FIG. 19, step 308, “park linear slide 118,display ‘Returning’ on display 220,” and the program returns to FIG. 18,step 302. If “Reverse limit switch 210 reached?” is NO, the programproceeds to FIG. 21, step 318, “Enough force?”

If FIG. 21, step 318, “Enough force?” is YES, the program proceeds toFIG. 21, step 320, “Increment dilation time variable,” and then to FIG.21, step 322, “Too much force?” If FIG. 21, step 318, “Enough force?” isNO, the program proceeds to FIG. 21, step 322 “Too much force?”

If FIG. 21, step 322 “Too much force?” is YES, the program proceeds toFIG. 21, step 323, “Reverse linear slide 118,” and then to FIG. 21, step324, “Not enough force?” If FIG. 21, step 322 “Too much force?” is NO,the program proceeds to FIG. 21, step 324, “Not enough force?”

If FIG. 21, step 324, “Not enough force?” is YES, the program proceedsto FIG. 21, step 325, “Move linear slide 118 forward,” and then to FIG.21, step 326, “Start button 212 pressed?” If FIG. 21, step 324, “Notenough force?” is NO, the program proceeds to FIG. 21, step 326, “Startbutton 212 pressed?”

If FIG. 21, step 326, “Start button 212 pressed?” is YES, the programproceeds to FIG. 19, step 308, “park linear slide 118, display‘Returning’ on display 220,” and then to FIG. 18, step 302. If FIG. 21,step 326, “Start button 212 pressed?” is NO, the program proceeds toFIG. 20, step 310, “Clear display 220, read sensor 204.”

At the end of the treatment, pressures and durations of each interval oftreatment can be transferred to a patient treatment record.

What is claimed is:
 1. A method for treating a stricture in a body lumencomprising (a) sensing pressure being exerted by a treatment device onthe stricture, (b) determining, with a controller, if enough force isbeing exerted on the stricture, (c) if enough force is being exerted onthe stricture, timing with the controller the application of enoughforce, (d) determining, with the controller, if too much force is beingexerted by the treatment device on the stricture, (e) if too much forceis being applied to the stricture, automatically decrementing with thecontroller the force being applied to the stricture, (f) determining ifnot enough force is being applied to the stricture, (g) if not enoughforce is being applied to the stricture, automatically incrementing withthe controller the force being applied to the stricture, and (h)automatically repeating (a)-(g) with the controller until (i) a desiredpressure has been maintained on the stricture for a desired time togradually relieve the stricture and widen the body lumen.
 2. A methodfor remodeling scar tissue in a body comprising (a) sensing pressurebeing exerted by a treatment device on the scar tissue, (b) determining,with a controller, if enough pressure is being exerted by the device,(c) if enough pressure is being exerted by the device, timing with thecontroller the application of enough pressure, (d) determining, with thecontroller, if too much pressure is being exerted by the device, (e) iftoo much pressure is being exerted by the device, automaticallydecrementing with the controller the pressure being exerted by thedevice, (f) determining if not enough pressure is being exerted by thedevice, (g) if not enough pressure is being exerted by the device,automatically incrementing with the controller the pressure beingexerted by the device, and (h) automatically repeating (a)-(g) with thecontroller until (i) a desired pressure has been maintained on the scartissue for a desired time.
 3. The method of claim 1, further comprisinginserting a balloon catheter into the body lumen, the body lumen beingone of a trachea and an esophagus.
 4. The method of claim 2, furthercomprising inserting a balloon catheter into a body lumen, the bodylumen being one of a trachea and an esophagus having the scar tissue. 5.The method of claim 4, wherein repeating (a)-(g) until (i) the desiredpressure has been maintained on the scar tissue for the desired timeincludes gradually relieving the stricture and widening the body lumen.